Stereoselective metabolism and pharmacokinetics of chiral drugs

A surprisingly large number of marketed drugs are chiral drugs. The pharmacokinetic profiles of chiral drugs generally differentiate between two enantiomers of racemic drug and the stereoselectivity is mainly due to the stereoselective interaction between the enantiomer and the active biological macromolecules in the living body. Stereoselective metabolism of chiral drugs may be responsible for much of the stereoselectivity observed in pharmacokinetics and are separated into three kinds of categories which contains substrate stereoselectivity, product stereoselectivity and substrate/product stereoselectivity. Meanwhile, impact of tereoselectivity on cytachrome P450 are presented and some illustrative examples are selected from therapeutics currently in use to illuminate the metabolism of chiral drugs.